<template>
  <header class="header">
    <h1>todos</h1>
    <input id="toggle-all" class="toggle-all" type="checkbox" v-model="isAll">
    <label for="toggle-all"></label>
    <input
      class="new-todo"
      placeholder="输入任务名称-回车确认"
      autofocus v-model="task" @keydown.enter="downFn"/>
  </header>
</template>

<script>
export default {
  props:['list'],
 data(){
  return {
    task:''
  }
 },
 methods:{
  downFn(){
    if(this.task.trim().length===0){
       alert('请输入内容')
       this.task=''
       return 
    }

    this.$emit('add',this.task)
    this.task = ""
  }
 },
 computed:{
  isAll:{
    set(val){
      return this.list.forEach(item=>item.isDone=val)
  },
  get(){
   return this.list.every(item=>item.isDone)
  }
 }
}
}
</script>